Gone to Lunch Indian Rope Trick

The basic plot is that a spectator signs a card which shows a boy climbing up the rope. However, when the spectator next looks at the card the boy has vanished, to be replaced by a sign saying OUT TO LUNCH. The Davenport advertisement, illustrated here, mentions that the back of the card has the explanation of the trick in a foreign language. Neither of the two versions of the trick shown here have printing on the back of the cards. Complete with instructions.